Six patients with spinal arachnoid cyst were treated at the Ryukyu University Hospital from 1990 to 2001. We evaluated the operative results retrospectively. The mean age of these six patients was 48 years (range : 13 to 72 years). They were consisted of one male and five females. All cysts occurred at the dorsal side of the spinal cord. Three cases had extradural arachnoid cyst, and the other three had intradural arachnoid cyst. All patients underwent surgery for cyst excision. For extradural arachnoid cyst, we recognized a stalk between the cyst wall and dura in all cases. Total excision was performed on two cases with tying of the stalk. Partial excision was performed in one case because of adhesion. For intradural arachnoid cyst, one case was treated with laminoplasty and total resection of the cyst, the other two cases were treated with laminectomy and partial cyst wall resection. After surgery, three cases of extradural arachnoid cyst and one case of intradural cyst treated with total resection showed no recurrence and recovered satisfactory. Whereas, the other two cases of intradural arachnoid cyst treated with partial cyst wall resection showed recurrence of cyst and one became worse at follow-up.
